Process of and mechanism for fabricating filled capsules



Feb. 5, 1952 R. P. SCHERER ET AL PROCESS OF AND MECHANISM FORFABRICATING FILLED CAPSULES 2 SHEETSSHEET 1 Filed May 11, 1948 641/225ear/ W Feb. 5, 1952 R. P. SCHERER ETAL 2,584,622

PROCESS 01 AND MECHANISM FOR FABRICATING FILLED CAPSULES Filed May 11,1948 2 SHEETS-SHEET 2 6A 49A 22A |8A |ek 22A M Z W k I '11 I I 20A 20A NENTORS POBL-Rffi 0/5952 Swa /z 6PM Patented Feb. 5, 1952 PROCESS OF ANDMECHANISM FOR FABRICATING FILLED CAPSULES Robert Pauli Scherer, Detroit,and John Otto Seller-er, Grrosse Eointe Park; Micln, assignors to R. P.Scherer Corporation, Detroit, Mich.-, a

corporation of Michigan Application May 11, 1948, Serial No. 26,384

8. Claims. {CL 181-9) This invention relates to improvements in aprocess of and mechanism for fabricating filled capsules. It relatesparticularly to the fabricating of the liquid filled gelatin capsules ofcommerce.

Heretofore such capsules have been fabricated in rotary die machines ofthe character disclosed in U. S. Patent 1,970,396 of August 14, 1934, toRobert P. Scherer, and also in reciprocating plate machines of thegeneral character illustrated in Patent 2,294,633 of September 1, 1942,to the same inventor. r

- In the machine illustrated in the last named patent, a bag formed oftwo gelatin sheets and filled with liquid capsule content material isplaced between two cooperating die plates. These two die plates areprovided with complementary capsule forming cavities. Each cavity issurrounded by an elevated cutting ledge. The two plates are supported tobe advanced toward each other against opposite faces of the liquidfilled bag. The liquid content material within the bag is urged into thepockets formed between those complementary areas of the sheets whichoverlie the cavities and the sheets are sealed together along'a linesurrounding each such pocket by the cooperating ledges of the diemembers thereby forming liquid filled capsules which capsules aresevered from the sheets by the ledges of the die members. v I

.In"' the reciprocating plate machines which antedated the Patent No.2,294,633, but which were'of the .same general character, a certainamount of the content material within the bag tended tocollectbetweenportions of the sheets outside ofv the capsule forming areas surmountingthecavities. Such portions of the sheetsremaining after the capsuleshave been cut therefrom are called the net. Asthis content material isexpensive, itwas common practice to salvage it fromflthe net. Theapparatus of said Schere'r Patent 2,29%,633-was devised to morecompletely forcethe liquid content material on to the capsuleformingareas of the sheet surmountingthe cavities. and to minimize thecollection of the content material within the net.

The instant application illustrates a flat reciprocating plate machineofthe general character illustratedin Patent'2',294,633 supra andconstitutes an improvement thereon. .The machine of thisapplication' isadapted to be set to advance suitable pressure pad members toward eachother angiag'ainst the gelatin sheets until the resistance oflered bythe'gelat'insheets reachesa predetermined value? 1 ween this resistancevalue is reached, further compression movement of the pressure pads isautomatically stopped. The pads are then held fixed at such advancedpositions against any possibility of retraction while the die plates areadvanced therebeyond and toward each other to form, seal and sever thecapsules from the sheets.

The movement of the pressure pads toward each other and against thegelatin sheets to press said sheets together until a predeterminedresistance isreached urges all of the content material from betweenthose portions of the sheets overlying the pressure pad members into thepocket areas overlying the capsule forming cavities of the die plates.wastage of content material in the net is therefore reduced to aminimum.

As the pressure pads are then positively held against retraction at suchpositions, while the die plates are advanced to seal the gelatin sheetstogetherabout the capsule cavities and form the capsules and to severthe capsules from the net, those portions of the gelatin sheets disposedbetween the ledges of the die plates are held against extrusion into thearea surrounding the capsule cavities between the pressure pads. Suchportions of the gelatin sheets are extruded from between the ledges ofthe die plates and into'the wall structure which goes to form thecapsule shell and therefore reinforces such shell and particularly thejoint formed between the two halves of the shell. Y

The instant application is a continuation in part of abandonedapplication Serial No. 576,238, filed February 5, 1945. e

Other objects, advantages and meritorious features will more fullyappear from the following description, appended claims and accompanyingdrawings:

Fig. l is a vertical sectional view through a pair of cooperating diemembers and associated mechanism embodying this invention.

Fig. 2 is a plan of'one of the die members shown in Fig. 1.

Fig. 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 2,illustrating the cooperating action of the fence or frame membersagainst the gelatin sheets.

Fig. 4 is a fragmentary sectional view taken on the same line as Fig. 3showing the cooperative action of the pressure. pad plates against thegelatin sheets ahead of the die members.

Fig; 5 is a fragmentary sectional view taken on the same line as Fig. 3showing the coopera- C tive action of the die members upon the gelatinsheets following compression of the sheets between the pressure pads.

Fig. 6 illustrates hydraulic operating mechanism for carrying out theprocess.

In Fig. 3 let I and i2 indicate two complementary gelatin or othersuitable plastic sheets with liquid content material l4 therebetween anddisposed between a pair of complementary spaced apart die plate,pressure pad, and fence assemblies. In the lower assembly a fence orframe 16 encircles a die plate 13 and a pressure pad 20 which padsuperimposes the die plate. The

die plate is provided with capsule cavities 22. Each cavity 22 issurrounded by a ledge 24 which ledge projects above the face of the dieplate. The pressure pad is provided with openings through which theledges extend as shown in Figs. 1 and 2.

In a simple reciprocating plate machine the gelatin sheet If) may bespread over the lower fence, the lower die and the lower pressure pad.Upon the sheet is delivered the desired amount of content material tofill the number of capsules to be formed by the die member. The sheetsags down as shown and a second sheet I2 is then spread thereover.

An upper cooperating complementary assembly including a die plate l8a, apressure pad 26a, and a fence 5a is provided. The upper die plate isprovided with capsule cavities 22a complementary to the cavities 22 andsurrounded by elevated cutting ledges 24a complementary to the ledges24.

The two cooperating assemblies are disposed within a stationaryframework 26. fence It is shown as supported by push rods 28. The pushrods are slidable through a fixed frame section 32. Springs 30 encirclethe rods and seat at their upper ends against the frame section 32 andseat at their lower ends against pistons 36 mounted on the rods to holdthe rods down. The pistons are disposed within hydraulic cylinders 31carried by a fixed frame piece 34.

The lower die plate I8 is supported by a push rod 38 which extendsslidably throughthe frame section 32 and is held down by a spring 40which spring seats at its upper end against frame section 32 and atitslower end against piston 42 mounted on the rod and slidable withinhydraulic cylinder 43. v

The lower pressure pad is supported by push rods 44, cross piece 41 andstruts 46 as shown in Fig. 6. Push rods 44 carry pistons 45 slidablewithin hydraulic'cylinders 41. Springs 46 are provided as shown in Fig.6 to exert downward pressure onthe push rods. The several push rods 28,38 and 44 are hydraulically actuated counted the spring resistance in adetermined sequence as hereinafter described.

The upper fence l6a, the upper die plate l8a and the upper pressure pad20a, are supported in a similar manner for reciprocation being providedwith operating push rods 28a, 38a and 4411, respectively The push rodsare so hydraulically actuated that the fence members l6 and I So arefirst moved as shown in Fig. 3 to hold the sheets [3 and i2therebetween. The pressure pads 20 and 20a are then moved to thepositions shown in Fig. 4 to compress the sheets [0 and I2 therebetween.The die plates are then moved as shown in Fig. 5 cutting through thegelatin sheets and forming and severing the capsules therefrom all asshown in Fig. 5.

. When the pressure pads are moved toward each The lower other to thepositions shown in Fig. 4, they move in response to hydraulic pressureoperating mechanism hereinafter described to such a position that theresistance of the gelatin to further movement reaches a predeterminedpoint. At this point the movement of the pressure pads toward each otherautomatically stops. This is accomplished as hereinafter described andit is this position that is shown in Fig. 4. At such position all of theliquid content of the material has been extruded from between thoseportions of the gelatin sheets 10 and I2 which overlie the pressure padsinto the spaces between those portions of the sheets which overlie thedie cavities.

When the die plates are moved together to seal the capsules about thecontent material and to sever'the capsules thus formed from the sheetsof gelatin or other capsule shell material, those portions of the sheetswhich are positioned between the ledges of the die plates are heldagainst extrusion into the space between the pressure pads because suchspace is filled with gelatin compressed between the pads. Such portionsof the sheet material are therefore caused to flow toward the capsulecavities. Being extruded toward the capsule cavities such gelatin entersinto the capsule shell and reinforces and strengthens the sameparticularly throughout the joint area formed between the two halveswhich make up the capsule shell. I

The hydraulic operating mechanism is illustrated schematically in Fig.6. In this Fig. 6 three hydraulic pumps50, 52 and 54 arediagrammatically illustrated as driven from a source of power 56. Thesepumps are conventional. Pump 50 has a lead 58 which through upper andlower branches 60 extends to the cylinders 31 and 310 which actuate thepistons 36 and 36a and through the plungers 28 and 28a moves the fencemembers Sand "in. Pump 52 has an outlet 62 which through upper and lowerbranches 54 extends to cylinders 41 and 41a to actuate the pistons and45a to advance the pressure pads 20 and 20a. Pump 54 has an outlet 66which through upper and lower branches 68 extends to cylinders 43 and43a to advance the pistons 42 and 42a to actuate the die plates l8 and18a.

These pumps are similar in character and capacitated to deliver therequired amounts of liquid. In the outlet of each pump is a 3-way valve10. These valves are adapted to be actuated through control mechanism 12so as to cause the pumps to deliver liquid to the cylinders or to causethem to deliver liquid to return outlets I4 which lead back to a sourceof liquid.

The outlets 58 and 62 from the pumps and 52 which'supply liquid to thecylinders 31, 31a,-

41, and 4111 are provided with check valves 18. These check valves areprovided in order that when the fence member 16 and 16a and the pressurepad members 20 and 20a are closed to the positions shown in Figs. 3 and4 respectively, and the liquid pressure reaches a predetermined valuedue to resistance of the gelatin sheets to further compression, therelief valves 18 in the outlets from the pumps 50 and 52 will open andpermit the bypassing of liquid back to the source. Upon the opening ofthe relief valves 18 with consequent flow of liquid therethrough anddiscontinuance of flow through the check valves 18, the'check valveswill'close and will maintain the determined pressure which has beenbuilt up -in; th nes and he for m in fence 5. members. and the pressure.pad members at the positions. shown. in Fig. 4;

There is a similar relief. valve 80in the outlet 55, from the pump 54but. this serves solely as a, relief valve for this pump outlet is notprovided with a check valve inasmuch. as this is the pump that. actuatesthe die plates. The check valves; serve the purpose in the lines. whichlead to the pressure pad cylinders and the. fence cylinders. ofpositively maintaining the pressure pads and. fence. members at; theiradvanced positionsv during the final advance of the die plates.

'Ilhe: single cylinders; 4.3 and 43a .whichv receive liquid to advancethe pistons .42 and 42a to move the. .die plates are shown as havingtwice the area of one. of. the pair of cylinders 31 or 41 and theseveral pumps and cylinders are so capacitated that the fence members,pressure pad members, and die plate members, are advanced in unison butin the relative positions shown inFig. 1 of the drawing 50 that theycome together successively as shown in Figs; 3, 4 and 5 to accomplishthe desired results.

- What we claimis:

1... In apparatus for use in themanufacture of capsules, in.combination, .a. pair of cooperating die platesprovided .in theircooperating. faces with complementary elevated cutting ledges, a

pressure pad associated with one die plate having openings to receivethe cutting ledges of the die plate therethrough, complementary framemembers adapted to hold complementary capsule forming sheets togetheralong a line surrounding an area filled with content material betweenthe plates, mechanism operableto advance one die plate toward thecooperating die plate to bring their complementary cutting ledgestogether through capsule sheet material disposed therebetween, pressuresensitive mechanism operable to advance said pressure pad in advance ofits associated die plate until the resistance of the capsule sheetmaterial ofiered to said advance reaches a predetermined value, saidlast mentioned mechanism responsive to such resistance to stop theadvance'of the pressure pad regard-v less of the distance advanced andpositively hold the pressure pad at the point to which advanced,

said die plate advancing mechanism being operable to advance the dieplate to bring the complementary ledges of the die plates together whilesaid pressure pad is held at advanced position.

2. In apparatus for use in the manufacture of capsules, in combination,a pair of complementary die plates provided in their respectivecooperating faces with complementary capsule forming cavities encircledby complementary ledges projecting above the faces of the die plates,complementary pressure pads superimposing the die plates and havingopenings through which the ledges are received, hydraulic operatingmechanism coupled with said pressure pads and die plates operable toadvance them relatively toward each other to compress capsule formingsheets between the pressure pads prior to compression of said sheetsbetween the die plate ledges, said hydraulic operating mechanismincluding means responsive to a determined resistance oifered by thecapsule forming sheets to advance of the pressure pads to stop saidadvance regardless of the distance advanced and hold the pressure padspositively at the point to which advanced and means operable upondiscontinuance of advance of the pressure. pads to advance the dieplates toward each other to bring their ledges together beyondthepressure pads.

6v 53,; Inapparatusror use in; the ma ufacture or capsules. incombination, a pair of cooperating die plates, exhibiting in theirrespective operating faces complementarycapsule forming cavities ens--circled by complementary elevated ledges, a pressure pad superposingeach die plateand having; openings proportioned to receive the. dieplate ledges ther., ethrough,v complementary frame members adapted tohold complementary capsule formingsheets together along alinesurrounding an area filled withcontent material between the pads,pressure pad advancing means responsive to. predetermined. resistanceoffered by said sheetst.0..- advance:- movement of the pads relatively.to-.-

wardeach. other for discontinuingv such movement and positively holding.the pads at such ad.- vanced position, and means for moving said dieplates ,relatively. toward each other to project theirledges; beyond thepressure pads and through the sheets: while said pads are held. attheadvanced. position.

4.. Ina. process of forming; filled capsules which embodies holdingcomplementary-portions of two sheets of plastic capsule forming materialtogether'along a line enclosing liquid capsule content materialformingabag filled with said liquid content: material, advancingcomplementary die plates and complementary pressure pads relative.- 1ytoward each other and toward opposite sides of said bag, thecomplementary faces of said die plates provided with complementarycapsule forming cavities encircled by complementary elevated sealing andcutting ledges and the complementary pressure pads provided withcomplementary openings therethrough received over said ledges of the dieplates, and advancing said complementary die plates and pressure pads insuch a manner that the pressure pads are advanced ahead of the dieplates and urge the sheets together therebetween in advance of the dieplates thereby urging the content material between the sheets'intopockets formed between complementary areas of the sheets overlying thecavities in the die plates, the improvement which comprises the steps ofcontinuing the advance of the pressure pads until a predeterminedresistance to such advance ofiered by the sheets is encountered andstopping the advance of the pressure pads at that position regardless ofthe distance the pads have advanced, and holding the pressure pads atthe positions at which they were stopped while continuing to advance thedie plates to seal the sheets together about the capsule cavities tothereby form sealed capsules and sever them from the sheets.

5. In a process of forming filled capsules which embodies the steps ofholding complementary portions of two sheets of plastic capsule formingmaterial together along a line enclosing liquid capsule content materialforming a bag filled with said liquid content material, and advancingagainst opposite walls of the filled bag complementary pressure pads anddie plates for forming and severing filled capsules, the improvementwhich comprises the steps of moving the pressure pads toward each otherin advance of the die plates until a predetermined resistance to suchmovement is encountered, stopping the movement of the pads at that pointand positively holding them in such advanced position while continuingto advance the die plates toward each other to thereby form and severthe capsules.

6. In a process of forming filled capsules which embodies the steps ofholding complementary portions of two sheets of plastic capsule formingmaterial together along a line enclosing liquid capsule content materialforming a bag filled with said'liquid content material, and advancingagainst opposite walls of the filled bag complementary pressure pads anddie plates for forming and severing filled capsules, the improvementwhich comprises the steps of moving the complementary pressure pads anddie plates toward each other with the pressure pads in advance of thedie -plates until a predetermined resistance to the m'ovement of thepressure pads is encountered, stopping the movement of the pads at thatpoint; and positively holding the pads in such advanced position whilecontinuing to advance the dieplates toward each other to thereby formand sever-the capsules.

7. Apparatus for making capsules from superimposed sheet material withfiller material disposedtherebetween comprising complementary die platesand pressure pads movable respectively toward one another, means formoving the pads in advance of the die plates until a predeterminedresistance to movement is encountered, means for stopping such movementof the pads at that die plates while the pads are held immobile tothereby form and sever the caspules.

8. Apparatus for making capsules from super-' imposed sheet materialwith filler material disposed therebetween comprising complementary -dieplates and pressure pads movable respectively for disconnecting from thepads their moving REFERENCES CITED The following references are ofrecord in the file oi this patent:

UNITED STATES PATENTS Number Name Date 1,970,396 Scherer Aug. 14, 19342,172,546 Riel Sept. 12, 1939 12,294,633 Scherer Sept. 1, 1942 Gary, Jr.Apr. 15, 1947

